High performance gel permeation chromatography (hp-gpc) is beingused in the study of asphalt cements. The use of a photodiode arrayspectrophotometric detector adds to the chemical information that may be obtained from the hp-gpc molecular size distribution by providing chromatograms at multiple wavelengths in the ultraviolet-visiblerange simultaneously. A three-dimensional image of the asphalt and spectra at various elution times are obtained. The result is improved knowledge of the conjugation/aromaticity of asphalt components of various hydrodynamic volumes. In this study, a group of 19 asphalt cements, from worldwide sources and representing a broad range of properties, was selected for eventual construction of a data base. These materials were sorted into three classes based on their chromatographic shapes. These classes appear to extend to temperature susceptibility (pvn) and aging index as well. Also investigated were a limited number of less common materials to determine the potential utility of the technique. These materials included sara fractions, viscosity-reduced, air-blown and solvent-deasphalted residua. This paper appears in transportation research record no. 1228, Asphalt mixtures and asphalt chemistry.
Abstract